Uploading foreign work

I found some very nice acapellas, some under public domain license(like this) and others under the CC-BY-SA license(like this one).

I would like to share it with you, but don’t know how to do it the best way. Should I just upload it with my account and put the name of the original author in front of it (also describing the situation in the description of course). Or is there some better method? Actually I am even not sure if you want foreign content to be posted on this site.

There have been some instances of PD samples incorporated in remixes here. In those instances, the uploader usually provides a link to the originating webpage in the description field of the remix it was used in.

The CC-SA case is different in that there may a conflict in licenses with other sources.

I actually meant to upload it as a pella, as I can’t do anything with them, but thought you can.

I already forgot about the BY-SA problem, not being mixable with Magnatune samples and many other sources. Still there are some really good PD samples, that I d like to share. In worst case I can open a forum thread for the samples I guess.